Cutter



C. C. PATTON Aug. 7, 1951 CUTTER Filed Aug. 15, 1948 l/ //LZ/AQ/ 1 WM W5 Patented Aug. 7, 1951 1948; Ser ial $124,163

ptembe1g8 19 47 teriafhfid the like an morejbarticularly cutters "which are particularlj adapted for "hand operati "small work shuns and on-ftheljoli in which a shearing blade of thistyp'e sfga'ictor i of fairly thinsheets of fairly'pliable naterial master each as; for instance, "and g/gimc steel plate has had to cultiefs bate arisen W In" thefirst'place the agenda between tnbiade and'tlijeinatei'ialbeing cutbecomes so great that v 'ilds i q eil a va glitter Between sucgssive==' h fth s ee m er a n has',

fi'o'rn theblad after each cut 'by' a ha n ner strolge or some other yiolent means;

bc ti frn jesi a been; a t fir a o ei wt sly known cutters hicl'fhai e" until th'present advantage is neces ary when cutting such thick r al t at a v a point on the blade fairly'close tothe point at which the blade is pivoted. This results-in there being ajfairlylargeangle between the blade and thef sheetinalterial which eauses the sheet ma he eut mustbe commenced at terial to slip backwards when gforce is applied to t e e i -blei extrr nely-diflicult-to initiate-a cut in fairly-thick sheet steel; using previously known cutters of this ap a v a Y The aboye mentioned} diiificultiesi have com- It-has been; found to be jfihfi: em le men e he tio po er Shears or acetylene torchesfor the cutting of the type of materialmentioned, Both of th'ese methods '40 are cumbersome; and excessively costly fo small work shops andonthe-job; H Thereis; moreover, theadded disadvantage that i -t* is not'ea sy to cut to exact dimensions with an acetylenetorch, and in the ease; of power-shears the edge :01 the:

out metal almostinvariably deformed,- makingextra work V be usedfor the purpose intended.

necessary betore the-cut material can Aaeozfdingly it is the object of the present in:

vention to provide--aoutter; of' thejtype described which is particularly "adapted; for hand "operation in small work shops and' capableof cutting fairl'y thick, rigidmaterial such as, for instance,

and 5- inch steel platew It is, another object of the invention to proout from under the blade when cutting; applied, t v

sheared but iior't dges of the bolst portioiijof th E vide'g such ,aQCutte which? lu freeingthe materi being cut from t eactififi f h bla 15011 t eraisin t each?successiveputi.

It is afu the'r vide, su hle imt uhi' z ziedi the"tendency' ofth inater1a1 'being' "cut provided for elir n i ati may freel'yjbe aduan Variousfother ob following main features; (d) (An f irregular "eutt .i a ede i h series ofeorrugations or (b')"A transversely"extending p I duced thickness extendinglcomnletely across the de d b i i l e ext d v upwardly froin the cutting. plane a' dis'tanee at least equal. to;

the maximurnthicknessfof u when h ade Jame ra s s! e it ea 1 313111 1 tion of reducedthickne'ss extending at least into the cutting plane when thebladeis insaid raised p itio f i (c) Stripping ineans nssoei ion it I thin portion fpr freeing the n aterial loeing cut from the binding actionbfthe blade upon=the raising thereof and. shiftingls'aidmaterial-to a position astride the thin bo rtioniof that, itmay befreely advance a subsequent; put. 7 Such 'siirippi ablyi Qornpris'e" seICtijIeIi plisit b Str p pins adapted to beseletiiielypositioned a esp h le boredth qugh t eahlagle for; that purpose ,a'dj

p E @9 U iq ene pl t ensL1 fulfi l purpojsewbufia' more Versatile i obt ned loythe proxisi en f l tionalole Q- ti9e 1t f r? a following subsidiai; feature taken singly grain v combination at laily raflgle;

tion gradually increases in thickness'fron'ii the pivoted end outwards, and increases in thickness atware-qr? he' binding reqr a ter,

ages of my fit n w l a ea in th i -l w n tail d 1 A cutter according toniy invention has the qe l i a a s fi m nn rthe ate i l-heme nut a a onhof req the work to be tout.

b lla delso re ries) ui from the cutting edge across the blade with the tapers meeting along a line running obliquely from the back of the blade to a point at or beyond the outer end of the cutting edge. A blade of this tapering nature materially reduces the friction which must be overcome by the stripping pins.

(2) A cutting edge of which the advanced end inclines upwardly slightly towards the pivot of the blade at a small angle to the main portion of the edge, thus decreasing the angle at which the cutting edge initially meets a piece of material being cut. This feature minimizes the tendency of the material to slide out from under the blade when force is applied.

(3) The bolster plates are of undercut design and on the blade is a slightly thickened portion at a point on the lower edge thereof and just to the pivot side of the thin portion of the blade. Such thickened portion is adapted, during a cut, to ride within the space defined by the undercut portions of the bolster plates, and during advancement of the work piece when the blade is in a raised position, wedges between the bolster plates thus pressing them apart, minimizing any tendency for the sheared out portion of the work piece to bind between the bolster plates.

One embodiment of the invention is illustrated in the accompanying drawings, in which Figure l is a perspective view of a handoperable cutter according to the invention. V

Figure 2 is a fragmentary side elevation of the cutting edge of the blade.

Figure 3 is a bottom elevation of the fragment of the blade shown in Figure 2.

Figure 4is an enlarged sectional view taken along the section A--A of Figure 2; and

Figure 5 is a fragmentary sectional view taken through the bolster plates along the section B-B of Figure 1 showing the undercut portions thereof.

Referring now more specifically to the drawings, a cutter according to the invention comprises two bolster plates IO and II which are suitably connected to base plates I2 and I3 which are secured to a base I4.

The bolster plates I and I are suitably bored to accommodate the pivot pin I which pivots the blade I6 about a suitable pivot hole I! formed therein.

A suitable handle member H is secured. to the outer end of the blade, I6 by bolts H3.

The sides of the blade I6 are formed with two tapers. One taper runs longitudinally, and the blade increases in thickness towards the handle end. A second taper runs in a transverse direction starting from the cutting edge I9 of the blade, which is parallel sided, and the blade increases in thickness in a transverse direction. The two tapers meet along a line 20 which runs obliquely across the blade, and is interrupted by a thin substantially parallel sided portion 2| of the blade.

The thin portion 2| runs from an advance portion of the cutting edge I9 across the blade. The thin portion 2| is of reduced thickness, being slightly thinner than the rest of the cutting edge I9 by an amount sufiicient to enable the said thin portion to pass freely through a cut made by the blade when the blade has been raised and the work is advanced following a cutting stroke. A thin portion 2| which is ap proximately 1%,; of, an inch thinner than the remainder of the cutting edge I9 has been found to be suitable.

Two holes 22 and 23 are provided in the blade adjacent the thin portion 2| on the side thereof remote from the pivot hole I1, and a stripping pin 24 is adapted to be selectively fitted in either one of the holes 22 and 23.

The cutting edge I9 is formed with a series of corrugations such as teeth 25, and an advanced portion thereof 26, which suitably extends across the end of the thin portion 2 I, isinclined slightly upwardly toward the pivot hole I! to reduce the angle at which the cutting edge 'will initially engage a piece of material being cut.

Adjacent the inner end of the cutting edge 2| is a thickened portion 2'! of the blade, which is adapted to operate in connection with the bolster plates l0 and II as will be described later.

The bolster plates l9 and II are of heavy substantiallyL-shaped cross section, and are bevelled at a suitable angle over their working portions 28 and 29 respectively. The bolster plates Ill and II are undercut throughout their length by cuts 3|! and 3| respectively, to produce clearance for the waste cuttings and a space in which the thickened portion 21 will bear against the bolster plates at a point which is preferably suitably bevelled as shown in dotted lines in Figure 5, and a slight spreading of the bolster plates will The operation of the blade l6 varies slightly depending upon the thickness of the material being out. w

When cutting fairly thin sheet metal up to approximately inch in thickness, the stripping pin is laced in the upper hole 22. With the blade I5 in the fully raised position the material to be cut is placed on the bolster plates, and a cut is commenced. As the cut proceeds, the material rides up the taper and the edges of the out are slightly spread apart. On completion of the cut the blade I6 is raised to a substantially vertical position. The material being cut is held down by the operator and works around the pin 24 as the blade is raised until the blade reaches the vertical position at which point the cut is astride the thin portion 2| of the blade and may freely be advanced therealong and along the bolsters for asecond cut.

Where thicker metal is to be cut, the stripping pin 26 is placed in the lower position in hole 23, and the pin 24 also acts as a stop during the cut, so that only the advance portion of the cutting edge I9 where the mechanical advantage is greatest is used in making the cut.

During subsequent cuts it is no longer necessary for the operator to hold down the material during the raising of the blade, because the effect of the taper of the blade upon the raising thereof is to further spread the cut at a point intermediate along its length by forcing the taper at the back of the blade in a downward direction, thus urging the material down on the bolster plates at that point as the blade is raised.

What I claim is:

1. A cutter of the type having a blade pivoted adjacent one end thereof between two bolster plates defining a cutting plane, said blade having a transversely extending portion of reduced thickness extending completely thereacross and positioned to extend upwardly from said cutting plane a distance at least equal to the maximum thickness of the work to be cut when the blade is in a raised position, said portion of reduced i i e iness xtend ng at. east into said cutti a 5 plane when the blade is in said raised position, and stripping means projecting from at least one side of said blade immediately adjacent the side of said portion remote from the pivoted end of the blade for engaging the upper side of the workpiece as the blade is raised following the cutting stroke to cause the workpiece to pivot therearound so that the cutting edges of the material of the workpiece lie astride said portion of reduced thickness. 1

2. A cutter as defined in claim 1 in which the blade is formed with a hole adjacent the side of said portion of reduced thickness remote from the pivoted end of the blade and in which said stripping means comprises a stripping pin designed to fit and be retained within said hole.

3. A cutter as defined in claim 1 in which said bolster plates are formed with longitudinally undercut portions immediately beneath said cutting plane and in which boss means are provided adjacent the lower edge of the blade on the side of said portion oi. reduced thickness nearest the pivoted end of the blade, said boss means being positioned to ride within the space defined by the undercut portions of the bolster plates while a cut is being made andto wedge between the bolster plates as the blade is raised to said raised position following a cut to force the bolster plates apart as said raised position is reached.

CHARLES CLAIR, PATTON.

REFERENCES CITED The following references are of record in the file of this patent:'

UNITED STATES PATENTS 

